Granted Patent
Utility
US 4,361,940 · App. 06/289,945
Slip-type elevator locking mechanism
Inventor:
Edward J. McFadden
Patented Case
View Patent ↗
Granted: Dec 7, 1982
Filed: Aug 4, 1981
Inventor
Edward J. McFadden
Assignee (at issue)
BJ-Hughes Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.